code: def cast_tensor_type(x, scale=1.0, dtype=None):
      if dtype == "fp16":
          # scale is for preventing overflows
          x = (x / scale).half()
      return x
  
file_path: mmdetection/mmdet/models/task_modules/assigners/iou2d_calculator.py
imports: import torch
  from mmdet.registry import TASK_UTILS
  from mmdet.structures.bbox import bbox_overlaps, get_box_tensor
label_desc: Use image node_id 1 for calling a global function with example usage: cast_tensor_type(x, scale, dtype) and returns: x